Vabnish fob



DANIEL MANSON SU'IHERLAND, F ASHGROVE, ENGLAND.

VARNISH FOR APPLYING T0 FABRICSOF AEROPL ANESL No Drawing.

To all whom it may concern:

Be it known that I, DANIEL MANsoN SUTHERLAND, a'sfibjeot of the King of Great Britain, residing at Ash rove, Sunbury Common, in the county of iddlesex, England, have invented new and useful Improvements in Varnishes or Do'pes More Especially Intended for Applying to the Fabrics of Aeroplanes and other Aerial Ma- 1 chines, of which the following is a specification.

In varnishes or dopes containing acetyl cellulose as at present used on the fabrics covering the wings and other parts of aeroplanes, or other aerial machines, triphenyl phosphate has been employed in as high a proportion as 15 parts of triphenyl phosphate to 85 parts of acetyl. cellulose, triphenyl phosphate being a scarce and expensive commodity. -v

The object of the present invention is to produce a suitable varnish or dope without the employment of triphenyl phosphate by the use of ingredients readily obtainable in this country and-less costly..

According to this invention I have discovered that inv place of triphenyl phosphate, boric acid can be advantageously employed; this is added in suitable proportions preferably to benzol, andtogether they form one of the ingredients of an acetyl cellulose varnish or dope, the benzol thus preferably displacing the alcohol or the like hitherto in use, so that in a varnish or dope according to this invention boric acid displaces triphenyl phosphate, or its equivalent while the alcohol, or the like, is

- preferably displaced by benzol, and a larger roportion of the benzol is used than has 40 een possible hitherto; such combination of benzol with boric acid, I term .borated benzol. I v

A dope or varnish so produced possesses excellent fire resisting qualities, the drying of the varnish is advantageously etarded, its viscosity diminished so that more highly concentrated solutions of the acetyl cellulose in the varnish can be used and the said varnish does not readily chill and turn white.

I have found the following examples Specification of Letters Patent.

Patented (lot. 28, 1919.

Application filed August 2, 1918. Serial No. 247,905.

nish or dope but the invention is not limited to the said examples or to the proportions stated given therein which will vary according to the consistency, viscosity and other particular properties required.

Although I have described the use of boric acid and. benzol, termed borated benzol, in the foregoin examples, for the production of acetyl ce lulose varnishes as more especially applicable for varnishing fabrics for aero machines, it must be-ufi derstood that the invention is not limited thereto but that the borated benzol may also be used in the productionof other varnishes ordopes for example, in varnishes or dopes in which nitro-cellulose or celluloid replaces the acetyl cellulose or its equivalent such for example as what are known as non-fl'am films.

; What I claim is 1. A cellulosic varnish com risin borated benzol as an essential ingre ient t ereof.

Ema/mple 1. (A thin varnish);

- Parts by f i v weight. Acetyl cellulose 6 Acetone or other equivalent solvent; 44 Benzol (preferably 90%) 24 Borated benzol (boric acid 10%, benzol I 9Q%) 24 Benzyl alcohol 2 Example 2. (A medium varnish).

Parts by weight. Acetyl cellulose 12 Acetone or other equivalent solvent 36 Benzol (preferably 90%) Borated benzol-boric acid 10%, benzol 90%). 25 Benzyl alcohol 3 2. A cellulosic Varnish comprising celname to this specification in the presence of lulosic material, a Solvent therefor, benzol, two subscrlbmg witnesses.

borated benzol and benzyl alcohol. DANIEL NSON SUTHEEMND 3. A cellulose varnish comprising acetyl 5 cellulose, acetone, benzol, berated benzol and Witnesses:

benzyl alcohol. v G. E. Tyson, In testimony whereof I have signed my L. WALTER. 

